U.S. patent number 10,190,529 [Application Number 15/726,618] was granted by the patent office on 2019-01-29 for marine engines having cylinder block cooling jacket with spacer.
This patent grant is currently assigned to Brunswick Corporation. The grantee listed for this patent is Brunswick Corporation. Invention is credited to Vinodh Kumar Balakrishnan, Trevor George, Thomas F. Nickols.
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United States Patent |
10,190,529 |
Nickols , et al. |
January 29, 2019 |
Marine engines having cylinder block cooling jacket with spacer
Abstract
A marine engine has a cylinder block having a plurality of
cylinders. A cooling jacket is formed in the cylinder block and is
configured to convey cooling fluid alongside the plurality of
cylinders. The cooling jacket has a top end and a bottom end. A
ledge is formed in the cylinder block. The ledge radially extends
into cooling jacket at a location between the top end and the
bottom end. A spacer is disposed in the cooling jacket and
supported by the ledge so that the spacer remains spaced apart from
the bottom end, thereby maintaining a lower cooling passage between
the spacer and the bottom end.
Inventors: |
Nickols; Thomas F. (Oakfield,
WI), George; Trevor (Eldorado, WI), Balakrishnan; Vinodh
Kumar (Fon du Lac, WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Brunswick Corporation |
Lake Forest |
IL |
US |
|
|
Assignee: |
Brunswick Corporation (Mettawa,
IL)
|
Family
ID: |
65032678 |
Appl.
No.: |
15/726,618 |
Filed: |
October 6, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02F
1/166 (20130101); F02F 1/14 (20130101) |
Current International
Class: |
F02B
75/18 (20060101); F02F 1/14 (20060101); F02F
1/16 (20060101) |
Field of
Search: |
;123/41.74,41.79,41.72 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
100980620 |
|
Dec 2009 |
|
KR |
|
100980955 |
|
Dec 2009 |
|
KR |
|
Primary Examiner: McMahon; Marguerite
Assistant Examiner: Kim; James
Attorney, Agent or Firm: Andrus Intellectual Property Law,
LLP
Claims
What is claimed is:
1. A marine engine comprising: a cylinder block having a plurality
of cylinders; a cooling jacket formed in the cylinder block and
defining a cooling jacket passage configured to convey cooling
fluid alongside the plurality of cylinders, the cooling jacket
having a top end and a bottom end; a ledge formed in the cylinder
block, the ledge radially extending the cooling jacket passage at a
location closer to the bottom end than the top end; and a spacer
disposed in the cooling jacket passage and supported by the ledge
so that the spacer remains spaced apart from the bottom end,
thereby maintaining a lower cooling passage between the spacer and
the bottom end; wherein the spacer comprises an elongated body and
a plurality of legs that extend upwardly from the elongated body
and maintain the elongated body in a seated position with respect
to the ledge; and wherein the body comprises a series of
cylindrical sections that are inwardly curved so as to follow an
outer curvature of the plurality of cylinders, and wherein the
plurality of legs are interdigitated amongst the series of
cylindrical sections and extend only towards the top end of the
cooling jacket from a juncture between adjacent cylindrical
sections in the series of cylindrical sections.
2. The marine engine according to claim 1, wherein the spacer
remains spaced apart from the top end, thereby maintaining an upper
cooling passage between the spacer and the top end.
3. The marine engine according to claim 1, wherein the ledge is one
of inner and outer ledges formed in the cylinder block and radially
extending into the cooling jacket towards each other.
4. The marine engine according to claim 3, wherein the spacer
comprises a tapered lower end that is sandwiched in a seated
position between the inner and outer ledges.
5. The marine engine according to claim 4, wherein the tapered
lower end extends downwardly past the inner and outer ledges.
6. The marine engine according to claim 1, wherein each cylindrical
section in the series of cylindrical sections has a convex bottom
surface that is oriented downwardly towards the bottom end of the
cooling jacket.
7. The marine engine according to claim 6, wherein each cylindrical
section in the series of cylindrical sections further has a convex
top surface that is oriented upwardly towards the top end of the
cooling jacket.
8. The marine engine according to claim 1, wherein the elongated
body radially abuts opposing internal sidewalls of the cooling
jacket in a manner that entirely prevents flow of cooling fluid
through the cooling jacket radially between the spacer and the
cooling jacket.
9. The marine engine according to claim 1, wherein the elongated
body is shaped so that an interstice is defined radially between
the elongated body and opposing sidewalls of the cooling jacket,
thereby allowing a relatively small amount of cooling fluid to flow
through the cooling jacket compared to a flow of cooling fluid at
the top and bottom ends of the cooling jacket.
10. The marine engine according to claim 9, wherein the spacer has
a cavity that defines part of the interstice.
11. The marine engine according to claim 1, wherein each respective
cylindrical section in the series of cylindrical sections has a
locking recess that extends upwardly from a lower end each
respective cylindrical section, and wherein the ledge in the
cooling jacket is received in the locking recess.
12. The marine engine according to claim 1, wherein the spacer is
one of a pair of spacers disposed in the cooling jacket, on
opposite sides of the plurality of cylinders.
13. The marine engine according to claim 12, wherein the cooling
jacket comprises a pair of cooling jacket passages that are located
on opposite sides of the plurality of cylinders and containing the
pair of spacers.
14. The marine engine according to claim 13, further comprising a
pump that pumps cooling fluid along a first side of the plurality
of cylinders and thereafter along an opposite, second side of the
plurality of cylinders.
15. The marine engine according to claim 1, wherein the spacer
allows less flow radially between the spacer and the cooling jacket
than along the top and bottom ends.
16. The marine engine according to claim 1, wherein the spacer
entirely prevents flow of cooling fluid radially between the spacer
and the cooling jacket.
17. The marine engine according to claim 1, wherein the spacer only
partially prevents flow of cooling fluid radially between the
spacer and the cooling jacket.
Description
FIELD
The present disclosure relates to marine engines, and more
particularly to cooling of cylinder blocks in marine engines.
BACKGROUND
U.S. Pat. No. 5,207,189 discloses a cooling system for an internal
combustion engine that eliminates stagnation of a coolant flowing
in a plurality of annular passages formed between a cylinder block
and a cylinder liner. Inflow and outflow passages are provided in
the annular passages and extend in a direction of an axis of the
cylinder liner. An inlet passage supplies a coolant to the inflow
passage. A guiding member is provided at an entrance of each of the
annular passages so as to lead a portion of a coolant to an
upstream side of each of the annular passages. A sufficient amount
of coolant flows through the annular passages of the cylinder
liner, and thus the wall of the cylinder liner can be cooled
efficiently.
U.S. Pat. No. 8,402,930 discloses a cooling system for a marine
engine having various cooling channels and passages which allow the
rates of flow of its internal streams of water to be preselected so
that heat can be advantageously removed at varying rates for
different portions of the engine. In addition, the direction of
flow of cooling water through the various passages assists in the
removal of heat from different portions of the engine at different
rates so that overheating can be avoided in certain areas, such as
the exhaust manifold and cylinder head, while overcooling is
avoided in other areas, such as the engine block.
U.S. Pat. No. 8,474,418 discloses a passage separating member
positioned in an axial direction of cylinder bores and causing a
spacer to contact a bottom surface of a water jacket. When the
separating member is inserted in the water jacket, the width of the
separating member is reduced due to elastic deformation, so that
the separating member can be arranged in the water jacket. After
being arranged, the separating member tightly contacts the inner
surface of the water jacket due to elastic restoration force. The
tight contact prevents the separating member from moving upward in
the water jacket. As a result, coolant is prevented from moving
between the upper portion and the lower portion with respect to the
separating member. The advantages of separate cooling of the
coolant in the upper and lower portions with respect to the
separating member are obtained. This reliably reduces the
temperature difference along the axial direction of the cylinder
bore forming body.
U.S. Pat. No. 8,763,568 discloses a spacer fitted inside a water
jacket of a cylinder block in an internal combustion engine. The
spacer is set so that a space formed between an inner peripheral
surface of the spacer and an inner wall surface of the water jacket
is smaller than a space formed between an outer peripheral surface
of the spacer and an outer wall surface of the water jacket.
Accordingly, even if the spacer is shifted in a radial direction,
the inner peripheral surface of the spacer comes into abutment on
the inner wall surface of the water jacket. Thereby, abutment of
the outer peripheral surface of the spacer on the outer wall
surface of the water jacket is prevented completely. Therefore,
hitting sounds of pistons can be blocked by the space between the
outer peripheral surface of the spacer and the outer wall surface
of the water jacket.
SUMMARY
This Summary is provided to introduce a selection of concepts that
are further described below in the Detailed Description. This
Summary is not intended to identify key or essential features of
the claimed subject matter, nor is it intended to be used as an aid
in limiting the scope of the claimed subject matter. In certain
examples disclosed herein, a marine engine has a cylinder block
having a plurality of cylinders. A cooling jacket is formed in the
cylinder block and is configured to convey cooling fluid alongside
the plurality of cylinders. The cooling jacket has a top end and a
bottom end. A ledge is formed in the cylinder block. The ledge
radially extends into cooling jacket at a location between the top
end and the bottom end. A spacer is disposed in the cooling jacket
and supported by the ledge so that the spacer remains spaced apart
from the bottom end, thereby maintaining a lower cooling passage
between the spacer and the bottom end.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure is described with reference to the following
figures. The same numbers are used throughout the figures to
reference like features and like components.
FIG. 1 is a perspective view of a cylinder block having a plurality
of cylinders.
FIG. 2 is a perspective view looking down at a first example of a
spacer for directing cooling flow alongside the plurality of
cylinders.
FIG. 3 a perspective view looking up at the first example.
FIG. 4 is a view of section 4-4, taken in FIG. 1, showing the first
example.
FIG. 5 is a perspective view looking down at a second example of
the spacer.
FIG. 6 is a perspective view looking up at the second example.
FIG. 7 is a view of section 4-4, taken in FIG. 1, showing the
second example.
FIG. 8 is a perspective view looking down at a third example of the
spacer.
FIG. 9 is a perspective view looking up at the third example.
FIG. 10 is a view of section 4-4, taken in FIG. 1, showing the
third example.
FIG. 11 is a perspective view looking down at a fourth example of
the spacer.
FIG. 12 is a perspective view looking up at the fourth example.
FIG. 13 is a view of section 4-4, taken in FIG. 1, showing the
fourth example.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a cylinder block 10 for use in an internal
combustion engine for a marine drive, for example an outboard motor
or a stern drive. The cylinder block 10 has a plurality of
cylinders 12 that can be arranged in a conventional in-line
configuration or V-configuration. As is conventional, each cylinder
12 typically has a cylinder liner 13 on its inner diameter, which
is abutted by the (not shown) reciprocating piston. A cooling
jacket 14 is formed in the cylinder block 10 and extends along and
is located radially adjacent to the cylinders 12. The cooling
jacket 14 includes a series of passages that are configured to
convey cooling fluid, for example cooling water, alongside the
outer diameters of the cylinder liners 13 and cylinders 12 so that
the relatively cold cooling fluid exchanges heat with the
relatively hot cylinder liners 13 and cylinders 12. In this
example, the cooling jacket 14 has two cooling jacket passages 26,
28 that are located on opposite sides of the cylinders 12 with
respect to each other. A conventional pumping device 30, such as an
electrical or mechanical pump, is configured to pump cooling fluid,
e.g. cooling water, into the cooling jacket 14 along the first
cooling jacket passage 26 on a first side of the cylinders 12 and
thereafter along the second cylinder passage 28 on an opposite,
second side of the cylinders 12. Similar arrangements for directing
cooling fluid through a cooling jacket in a marine drive are well
known and disclosed, for example, in the above-incorporated U.S.
Pat. No. 8,402,930.
Through research and experimentation, the present inventors have
determined that cooling systems for marine engines, particularly
open loop cooling systems that pump cooling water from the body of
water in which the marine vessel is operating through the engine
block, often overcool the liners in the cylinders. This can cause
poor fuel preparation, which results in fuel dilution in the engine
oil and high hydrocarbon concentration in emissions. The present
inventors have also determined that engine cylinders typically
generate the most heat at the top and bottom of the cylinder, where
the piston dwells (i.e., reverses direction). As such, it would be
advantageous to cool the top and bottom of the cylinder bore, where
the piston dwells, while not providing as much cooling to the
center of the cylinder, where the piston does not dwell. This can
alleviate the problems with over-cooling the cylinder liners, as
described above. The present disclosure is a result of the present
inventors' endeavors to overcome these disadvantages in the prior
art.
Referring to FIGS. 4, 7, 10, and 13, the cooling jacket 14 has a
top end 16 and a bottom end 18 relative to the centers of the
respective cylinders 12. A ledge configuration 40 is formed in the
cylinder block 10 in the cooling jacket 14. The ledge configuration
40 extends into the cooling jacket 14 at a location between the top
end 16 and bottom end 18. In the illustrated example, the ledge
configuration 40 has both inner and outer ledges 22, 24, each being
formed in the cylinder block 10 and radially extending into cooling
jacket 14 towards each other.
FIGS. 2-4 depict a first example of a spacer 32 according to the
present disclosure. As shown in FIG. 4, the spacer is disposed in
the cooling jacket 14 and supported by (i.e. seated on) the ledge
configuration 40 so that it remains spaced apart from the bottom
end 18 of the cooling jacket 14, thereby advantageously maintaining
a lower cooling passage 34 between the spacer 32 and the bottom end
18. As further described below, the spacer 32 also remains spaced
apart from the top end 16 of the cooling jacket 14, thereby
maintaining an upper cooling passage 36 between the spacer 32 and
the top end 16.
In the illustrated example, the spacer 32 has a tapered lower end
38 that extends downwardly past and is seated between the inner and
outer ledges 22, 24. Referring to FIGS. 2 and 3, the spacer 32
includes an elongated body 41 and a plurality of legs 42 that
extend upwardly from the elongated body 41 and are configured to
maintain the elongated body 41 in the seated position shown in FIG.
4 with respect to the ledge configuration 40. More specifically,
the legs 42 are elongated and sized so as to engage the top of the
cooling jacket 14 (e.g. on a not-shown conventional cylinder head
on the cylinder block 10) so that the elongated body 41 cannot
drift upwardly in the cooling jacket 14. Rather, the legs 42 force
the spacer 32 to remain seated with respect to the ledge
configuration 40 so that the noted upper cooling passage 36 is
maintained. In this example, the elongated body 41 includes a
series of semi-cylindrical sections 44 that are inwardly curved so
as to follow an outer curvature of the respective cylinders 12 and
respective cooling jacket passages 26, 28. Each semi-cylindrical
spacer section 44 has a convex bottom surface 46 that is orientated
downwardly (i.e. projects downwardly) towards the bottom end 18 of
the cooling jacket 14. Each semi-cylindrical section 44 also has a
convex top surface 48 that is orientated upwardly (i.e. projects
upwardly) towards the top end 16 of the cooling jacket 14. The legs
42 are interdigitated amongst the semi-cylindrical sections 44 and
extend from a juncture 50 located between and connecting adjacent
semi-cylindrical sections 44.
In the example shown in FIGS. 2-4, each cylindrical section 44 has
opposing sidewalls that are aligned with the sidewalls of the
cooling jacket 14. Each semi-cylindrical section 44 can be sized
(in relation to the cooling jacket 14) so as to prevent flow of
cooling fluid to flow through the cooling jacket 14 radially
between the spacer 32 and the sidewalls of the cooling jacket 14.
Alternately, each semi-cylindrical section 44 can be sized so as to
allow a relatively small amount of cooling fluid to flow through
the cooling jacket 14 radially between the spacer 32 and the
sidewalls of the cooling jacket 14, as compared to the flow of
cooling fluid at the top and bottom ends 16, 18 through the upper
and lower cooling passages 34, 36.
In the example shown in FIGS. 5-7, each semi-cylindrical section 44
of the spacer 32 forms a cavity 52 that defines an interstice
located radially between the elongated body 41 and the opposing
sidewalls of the cooling jacket 14, thereby allowing a relatively
small amount of cooling fluid to flow through the cooling jacket 14
as compared to the flow of cooling fluid at the top and bottom ends
16, 18. Note that the example shown in FIGS. 5-7 differs from the
example shown in FIGS. 1-4, having opposing sidewalls that are
aligned with each other without defining an interstice and aligned
with the inner sidewalls of the cooling jacket 14.
The example shown in FIGS. 8-10 is similar to the example shown in
FIGS. 2-4 except the tapered lower end 38 is longer so that it
extends further downwardly past the inner and outer ledges 22, 24.
Also, the spacer 32 has inner and outer ledges 54, 56 that extend
along the sidewalls of the semi-cylindrical sections 44 and
correspond to the inner and outer ledges 22, 24 in the ledge
configuration 40. The inner and outer ledges 54, 56 are configured
(located, sized and shaped) so that they abut the inner and outer
ledges 22, 24 when the spacer 32 is seated in the cooling jacket
14, as shown in FIG. 10.
The example shown in FIGS. 11 and 12 is similar to the example
shown in FIGS. 8-10, except the inner and outer ledges 54, 56 do
not extend along the entire sidewalls of the semi-cylindrical
sections 44, but rather are part of a locking recess 58, 60,
respectively, that extends upwardly from the tapered lower end 38
of each respective semi-cylindrical section 44. The location, shape
and size of the locking recess 58, 60 corresponds to the location,
shape and size of the inner and outer ledges 22, 24 in the cooling
jacket 14 so that the locking recesses 58, 60 receive the inner and
outer ledges 22, 24 when the spacer 32 is inserted into the cooling
jacket 14, as shown in FIG. 13. The locking recesses 58, 60 have
sidewalls that extend upwardly from the tapered lower end 38 of the
respective semi-cylindrical section 44 and each of the inner and
outer ledges 22, 24 has corresponding sidewalls that align with the
locking recesses 58, 60.
It will thus be seen that the spacer 32 is advantageously
configured to allow less flow between the spacer 32 and the cooling
jacket 14 than along the top and bottom ends 16, 18. In certain
examples, the spacer 32 entirely prevents all flow of cooling fluid
alongside the spacer 32 between the spacer 32 and the cooling
jacket 14.
According to examples in the present disclosure, the spacer 32 is
advantageously configured to either block or slow down flow of
cooling fluid in the cooling jacket adjacent to the center of the
cylinders--which typically are the coolest locations. The spacer 32
advantageously provides a means for controlling velocity of cooling
fluid flow through the center of the cooling jacket. The ledge
configuration 40 and its interaction with the spacer 32
advantageously ensures that a precisely sized lower cooling passage
is maintained in the cooling jacket, thus enhancing efficiency of
the cooling process, while avoiding the need for separating legs on
the bottom end of the spacer. The geometry of the spacer can vary
from the examples shown, and for example can have a flat lower end
across the width of the cylinder or have varying geometry to
achieve desired flow velocity and cooling fluid-wetted areas of the
liner.
In the present description, certain terms have been used for
brevity, clarity and understanding. No unnecessary limitations are
to be inferred therefrom beyond the requirement of the prior art
because such terms are used for descriptive purposes only and are
intended to be broadly construed. The different apparatuses,
systems, and methods described herein may be used alone or in
combination with other apparatuses, systems, and methods. Various
equivalents, alternatives and modifications are possible within the
scope of the appended claims.
* * * * *